USGS Body-Wave Moment Tensor Solution
SOUTH OF MARIANA ISLANDS
12/09/11 16:36:50.49 Epicenter: 11.885 143.146 MW 5.8 USGS MOMENT TENSOR SOLUTION Depth 8 No. of sta: 73 Moment Tensor; Scale 10**17 Nm Mrr= 4.16 Mtt=-4.93 Mpp= 0.78 Mrt= 5.04 Mrp= 1.17 Mtp=-1.20 Principal axes: T Val= 6.46 Plg=66 Azm=345 N 1.02 1 78 P -7.48 24 168 Best Double Couple:Mo=7.0*10**17 NP1:Strike= 77 Dip=69 Slip= 89 NP2: 261 21 93
The figure above shows a visual representation of the style of faulting (focal mechanism) derived from the estimated moment tensor. Shaded areas show quadrants of the focal sphere in which the P-wave first-motions are away from the source, and unshaded areas show quadrants in which the P-wave first-motions are toward the source. The dots represent the axis of maximum compressional strain (in black, called the "P-axis") and the axis of maximum extensional strain (in white, called the "T-axis") resulting from the earthquake.